core-lightning/anchor.c
Rusty Russell 3a62a9172d Create bitcoin_tx helper.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-30 20:12:14 +09:30

92 lines
2.7 KiB
C

#include "anchor.h"
#include "bitcoin_tx.h"
#include "overflows.h"
#include "pkt.h"
#include "perturb.h"
#include "bitcoin_script.h"
struct bitcoin_tx *anchor_tx_create(const tal_t *ctx,
const OpenChannel *o1,
const OpenChannel *o2,
size_t **inmapp, size_t **outmapp)
{
uint64_t i, n_out;
struct bitcoin_tx *tx;
u8 *redeemscript;
size_t *inmap, *outmap;
if (add_overflows_size_t(o1->anchor->n_inputs, o2->anchor->n_inputs))
return tal_free(tx);
n_out = 1 + !!o1->anchor->change + !!o2->anchor->change;
tx = bitcoin_tx(ctx, o1->anchor->n_inputs+o2->anchor->n_inputs, n_out);
/* Override version to use lesser of two versions. */
if (o1->tx_version < o2->tx_version)
tx->version = o1->tx_version;
else
tx->version = o2->tx_version;
/* Populate inputs. */
for (i = 0; i < o1->anchor->n_inputs; i++) {
BitcoinInput *pb = o1->anchor->inputs[i];
struct bitcoin_tx_input *in = &tx->input[i];
proto_to_sha256(pb->txid, &in->txid.sha);
in->index = pb->output;
/* Leave inputs as stubs for now, for signing. */
}
for (i = 0; i < o2->anchor->n_inputs; i++) {
BitcoinInput *pb = o2->anchor->inputs[i];
struct bitcoin_tx_input *in
= &tx->input[o1->anchor->n_inputs + i];
proto_to_sha256(pb->txid, &in->txid.sha);
in->index = pb->output;
/* Leave inputs as stubs for now, for signing. */
}
/* Populate outputs. */
if (add_overflows_u64(o1->anchor->total, o2->anchor->total))
return tal_free(tx);
/* Make the 2 of 2 payment for the commitment txs. */
redeemscript = bitcoin_redeem_2of2(tx, o1->anchor->pubkey,
o2->anchor->pubkey);
tx->output[0].amount = o1->anchor->total + o2->anchor->total;
tx->output[0].script = scriptpubkey_p2sh(tx, redeemscript);
tx->output[0].script_length = tal_count(tx->output[0].script);
/* Add change transactions (if any) */
n_out = 1;
if (o1->anchor->change) {
struct bitcoin_tx_output *out = &tx->output[n_out++];
out->amount = o1->anchor->change->amount;
out->script_length = o1->anchor->change->script.len;
out->script = o1->anchor->change->script.data;
}
if (o2->anchor->change) {
struct bitcoin_tx_output *out = &tx->output[n_out++];
out->amount = o2->anchor->change->amount;
out->script_length = o2->anchor->change->script.len;
out->script = o2->anchor->change->script.data;
}
assert(n_out == tx->output_count);
if (inmapp)
inmap = *inmapp = tal_arr(ctx, size_t, tx->input_count);
else
inmap = NULL;
if (outmapp)
outmap = *outmapp = tal_arr(ctx, size_t, tx->output_count);
else
outmap = NULL;
perturb_inputs(o1->seed, o2->seed, 0, tx->input, tx->input_count,
inmap);
perturb_outputs(o1->seed, o2->seed, 0, tx->output, tx->output_count,
outmap);
return tx;
}